The present invention relates generally to a circuit breaker circuitry for protecting a power source from electrical faults.
Many devices known in the art are useful for protecting power sources from electrical faults. There are at least three types of electrical faults: a ground fault, a transient fault, and an arc fault. A ground fault occurs when a grounded conductor comes into contact with electrical circuitry, causing an excessive current flow in that circuitry. A transient fault occurs when a grounded conductor briefly comes into contact with an electrical circuitry, causing a temporary excessive current flow in that circuitry. As a result of the excessive current drawn by ground and transient faults, power supplies can become overloaded, and the load that a power supply is meant to power ends up receiving little or no current. An arc fault occurs when an arc is struck between two conductors that are not in physical contact but are close to each other. An arc can produce high temperatures in its vicinity, which can create a fire hazard.
Existing devices for protecting power sources from electrical faults use thermal sensors, magnetic sensors, and/or current sensors to detect electrical faults. For these devices, it is necessary to select and calibrate their sensors to accommodate the current drawn by the load for proper operation, making the existing fault protection devices load dependent. The process of selecting and calibrating particular sensors to the current drawn by the load is time consuming and expensive. Furthermore, these sensors must be recalibrated when the current drawn by the load changes significantly or if a different load is used.
Accordingly, there exists a need for an electrical fault detection and protection device that operates independently of the load so that no calibration of the sensor is needed and is cost-effective to construct.
A circuit breaker circuitry in accordance with the present invention operates independently of the load to which a power source is connected. In addition, the preferred circuit breaker circuitry includes a time delay circuitry to prevent false detection of electrical faults resulting from current spikes that may occur when connecting the power supply to the load.
Preferably, the circuit breaker circuitry comprises a control circuitry that connects a power source to its load. The control circuitry disconnects the power source from the rest of the circuitry when an electrical fault is detected.
Preferably, the circuit breaker circuitry also comprises a sensor circuitry that detects electrical faults by monitoring the voltage drop across the control circuitry. When an electrical fault occurs in the circuit, a large current is drawn causing a significant potential drop across the control circuitry. The potential drop is in turn detected by the sensor circuitry. If an electrical fault threatens to interfere with the proper operation of the power supply, the sensor circuitry causes the control circuitry to disconnect the power source from the electrical faults, thus protecting the power source.
After the electrical fault has passed or is removed and a circuit breaker circuitry is reset, either manually or automatically, power returns to the control circuitry and the connection between the power source and the load is restored. Preferably, the time delay circuitry delays the activation of the sensor circuitry. This delay functions to shield the sensor circuitry from any current spikes that may occur when connecting the power source to the load and prevents false detection of electrical faults.
Preferably, the circuit breaker circuitry also includes a fault protection condition indicator for indicating whether the circuit breaker circuitry is working properly.